Screen



April 1935.. A. c. DURDIN, JR 1,999,149

SCREEN Filed Dec. 19, 1952 d She'ets-Sheet l INVENTOR. Magus/u; 6 30/070 J/r fiJATTORNEY.

April 23, 1935.

A. c. DURDIN, JR 1,999,149

SCREEN Filed Dec. 19, 1932 2 Sheets-Sheet 2 INVENTOR.

WATTORNEY.

Patented Apr. 23, 1935 SCREEN Augustus C. Durdin, In, Chicago, to Chicago Pump Company, C corporation of Illinois Application December 19, 1932, Serial No. 647,912

9 Claims. (Cl. 210152) This invention relates to screens and its principal object is to provide an arrangement of parts whereby the screen is automatically cleaned during its operation. The invention has reference more particularly to rotating sewage screens composed of spaced ring-like members arranged in the form of a drum and acting to intercept solids which are .too large to pass through the slots between the ring-like mem- 0 bers. Usually a comb or other toothed member is associated with the drum-like structure with its teeth entering into the slots and serving to clear the slots of material that gathers therein. One object of this invention is to provide selfcleaning means so arranged that at least once or more during each complete rotation of the drum, the slots and teeth are cleared of the mass, thereby leaving the slots more nearly free of dbris and providing for a maximum flow of liquid.

The invention consists in the several novel features hereinafter fully set forth and claimed.

The invention is clearly illustrated in the accompanying drawings, in which:

Fig. 1 is a perspective view of a screen'embodying a simple form of the present invention;

Fig. 2 is a detail plan of one of the rings which comprise the drum; r

Fig.- 3 is a side elevation of the ring seen in Fig.

Fig. 4 is a plan of a slightly modified form of ring;

Fig. 5 is a view of the screen partly in side elevation and partly in vertical section; and

-Fig. 6 is a horizontal section taken on the line 65 of Fig. 5.

Referring to said drawings, the reference character Ill designates a sewage or other channel, which is provided with an opening II in its bottom, that communicates with a duct l2 that carries off the strained liquid. At the end of the channel I0 is a hopper l3 in which the screenings are collected. Desirably the bottom of the hopper I3 is below that of the channel l0, and a chute M leads down from the bottom of the channel to that of the hopper.

The screen is provided with a pedestal 15 mounted adjacent the opening H, and the pedestal has an arm l6 formed thereon which supports a bearing head l1. At the top of the pedestal is a motor base I8 on which is mounted an electric motor l9 which, through a reduction gearing, enclosed in a housing 20, drives a shaft 2i. A screen shaft 22 journaled in the bearing head I! is coupled to the shaft 2| by a coupling 11]., assignor hicago, 11]., a

22*. The drum or screen proper is secured to and driven by the shaft 22, and desirably the uppermost ring of the drum is extended into the hollow of the drum in the form of a coned head 23 which is rigidly secured to the shaft 22 and carries the drum.

The drum is preferably composed of a plurality of rings 24 supported in spaced relation to provide annular slots or passages between them, through which the liquid may pass in its course from the channel In to the opening H. Solids which will not pass through the slots are intercepted by the rings, and thereafter delivered to the screenings hopper l3, from which they may be collected by any of the present methods.

The rings are provided with lugs 28 usually on their inner sides,- to receive studs or long bolts- 36 with nuts on their ends to hold the assembled rings together. In order to provide the proper spacing of the rings the lugs 28 have offsets 29 which are milled to present an accurate set up.

In operation, the drum is rotated, the liquids flowing through the slots between the rings and passing down through the opening I l and thence on through the duct l2. The solids are intercepted by the rings,-and to prevent matter from accumulating in the slots and thereby clogging them, a comb or toothed scraper is provided,

which has teeth 25 that enter the slots and rid them of accumulated matter as the drum revolves. The teeth 25 are preferably secured to the pedestal l5 by a clamp bar 26 fastened upon the teeth by bolts or cap screws 21. As the drum rotates, screenings are collected by the teeth 25, and the accumulation of the screenings causes the excess to settle into the screenings hopper.

To give relief to the screening operation, a recess is formed in the periphery of the rings at one or more places, by directing the faces 30 of the rings inwardly as is seen in Fig. 2. It will be observed that during the rotation of the drum, the teeth 25 of the comb emerge from the slots and enter the open spaces. Matter which has been carried against the teeth is free to fall through the open spaces, thereby ridding the teeth of the accumulated matter and permitting them to re-enter the slots, with the major portion of the accumulated mass removed therefrom.

One set of the faces 30 of the recess slopes gradually toward the cylindrical face of the drum, thereby enabling the teeth 25 to re-enter the slots gradually, thus relieving the drum of any excessive strain at the time the teeth re-enter the slots.

The oifsets 29 present cutting edges 3| which co-operate with the teeth 25 to comminute the screenings that collect in the slots. In this way, the slots are kept clear of solid and semisolid matter, thereby permitting a maximum flow of liquid through the screen.

Desirably the rings are formed with reduced ribs 32 on their inner sides, and the rims thereof are uniformly machined to provide slots of even width. The holes 33 for the studs or bolts 36 are machined so that the rings may be assembled into a uniform structure throughout.

In the modified form of ring illustrated in Fig. 4 a plurality of recesses 34 are formed in'the periphery of the ring and cutting edges 35 are provided on the lugs for co-operating with the teeth of the comb to comminute the material. The lugs form the continuations of the walls of the ring at the re-entrant portions and being made relatively narrow they do not necessitate any appreciable loss of passage through the spaces between the rings.

I claim as new and desire to secure by Letters Patent:

1. A screen comprising a cylindrical screening drum having a recess extending inwardly from the cylindrical face of its wall, one face of the recess sloping gradually toward the cylindrical face of the drum, and the latter being formed with circumferential slots extending continuously from the sides of said recess, and rigid teeth extending into said slots, the drum and teeth being rotatable, one relative to the other, and said recess providing a space for the teeth to emerge from the slots, whereby intercepted matter is free to escape from the teeth, and the sloping face of the recess permitting gradual re-entrance of the teeth into the slots. 7

2. A screen comprising a cylindrical wall having a recess extending inwardly from its outer face, and circumferentially disposed slots extending therefrom, lugs disposed on one side of the cylindrical wall and being formed with cutting edges, and teeth extending into said slots, said wall and teeth being relatively rotatable, whereby the teeth traverse the slots, and emerge into said recess, the cutting edges of the lugs and the teeth serving to comminute material caught therebetween.

3. A screen comprising a cylindrical wall having a recess extending inwardly from its outer face, and circumferentially disposed slots extending therefrom, lugs disposed on one side of the cylindrical wall, certain of said lugs being located at one side of said recess, and being formed with cutting edges, and teeth extending into said slots, said will and teeth being relatively rotatable, whereby the teeth traverse the slots, and emerge into said recess, the cutting edges of the lugs and the teeth serving to comminute material caught therebetween.

4. A screen comprising a cylindrical wall composed of spaced rings each having a recess extending inwardly from its outer face, lugs on one side of the rings spacing them apart to leave slots that extend from the recess, said lugs being formed with cutting edges, and rigid teeth extending into said slots and co-operating with said cutting edges to comminute material entering the slots, the wall and teeth being relatively rotatable, whereby the teeth traverse the slots and emerge into the recess.

5. A-screencomprising a rotatable cylindrical wall composed of spaced rings each having a recess extending inwardly from its outer face, one face of each recess sloping gradually toward the periphery of the ring, and the several recesses forming a gap in the cylindrical wall extending lengthwise thereof, lugs on one side of the rings spacing them apart to leave slots therebetween, and stationarily mounted rigid teeth extending into said slots and emerging into the gap in the wall as it passes by the teeth during the rotation of the wall, the sloping faces of the recesses permitting gradual re-entrance of the teeth into the slots.

6. A screen comprising a cylindrical wall having circumferentially disposed slots therein, lugs disposed on one side of the cylindrical wall in the same planes as the slots, and being formed with cutting edges, and teeth extending into said slots, said wall and teeth being relatively rotatable, whereby the teeth traverse the slots, and co-operate with the cutting edges of the lugs to comminute material caught therebetween.

7. A screen comprising a cylindrical wall having circumferentially disposed slots therein, lugs disposed on the inner side of the cylindrical wall in the same plane as the slots, and being formed with cutting edges, and teeth extending into said slots, said wall and teeth being relatively rotatable, whereby the teeth traverse the slots and cooperate with the cutting edges of the lugs to com minute material caught therebetween.

8. A screen comprising a cylindrical wall composed of spaced rings, lugs on one side of the rings spacing them apart to leave slots therebetween,.

said lugs being formed with cutting edges, and

rigid teeth extending into said slots, the wall and teeth being relatively rotatable, and the teeth and cutting edges of the lugs co-operating to comminute material caught therebetween.

9. A screen comprising a cylindrical straining wall comprising continuous rings, spaced apart to leave slots therebetween, lugs joining the rings one with the other, cutting edges formed on said lugs, and rigid teeth entering said slots and cooperating with said cutting edges to comminute matter, said wall and teeth being relatively rotatable. I

AUGUSTUS C. DURDIN, JR. 

